Automatic transmission



Dec. 4, 1951 E. J. FARKAS AUTOMATIC TRANSMISSION original Filed Aug. 22, 1945 4 Sheets-Sheet l QNIJ NN\ Si! DCC. 4, 1951 E. J, FARKAS Re. 23,436

AUTOMATIC TRANSMISSION Original Filed Aug.' 22, 1945 4 SheetSSheet 2 Dec. 4, 1951 Original Filed Aug. 22, 1945 E. J. FARKAS Re. 23,436

AUTOMATIC TRANSMISSION 4 Sheets-Sheet 3 JyLi Dec. 4, 1951 E. J. FARKAS AUTOMATIC TRANSMISSION 4 Sheets-Sheet 4 Original Filed Aug. 22, 1945 l l NIMHHHU INVENTOK so as to conform to the Riued Dee. 4, i951 23,436 AUTOMATIC TRANSMISSION Eugene J. Farkas,

Serial No. 611,975, Au for reissue December Laguna Beach, Calif., assignor to Ford Motor Company, corporation of Delaware Original No. 2,528,584,

Dearborn, Mich., a

dated November 7, 1950,

gust 22, 16,

1945. Application 1950, Serial No. 201,167

Claims. (Cl. 'I4- 732) Matter enclosed in heavy brackets l appears in the original patent but roms nu part of uns reissue speciiication; matter printed in italics indicates the additions made by reissue.

This invention relates to a transmission; and, more particularly, in which mechanical and uid power transmitting means are combined and automatically operated to obtain maximum eiilciency and smoothness in torque conversion in motor velilcles.

An object of this invention is to provide a mechanical power path for the higher forward speeds, while incorporating a duid power element in the low and reverse speeds. Another object is to apply complete automatic operating means to a transmission oi the combined hydraulic planetary gear type to obtain smooth transition between the successive stages of operation. Still another object is to devise an automatic, hydraulically operated control means particularly applicable to such transmissions and forming an internally disposed part thereof; and which is inherently so flexible and responsive in operation that the transition between stages will be eected quietly and smoothly whether the vehicle speed is increasing or decreasing and which will effect the precise operation called for under the particular circumstances.

One of the principal advantages of the present construction is that the operation or the hydraulic coupling is limited to the lower speeds at which the coupler efliciency is not too important a factor and that in the upper ranges the drive is directly through a more or less conventional mechanical transmission. It follows from this that automatic means are provided to render the hydraulic coupling inoperative under adv vanced speed conditions and to return it to operation when the speed decreases to a point at which such operation is again feasible. These operations are conducted automatically by the control mechanism itself and this control mechanism requires no exterior control during either advancing or declining speeds to be completely eilective. Indeed, the only manual control required is the selection oi the direction of operation. In addition, the transmission is immediately responsive to demands for increased acceleration, or the automatic feature may be overridden when a higher torque is required for -a longer period. In order to adapt a transmist sion of this type to current automatic practice, it is essential that the component be so arranged limited spaces-both longitudinal and transverse-now available.

to that type of transmission verse, Second and thus, the vehicle responds instantly to demands for increased speed and will readapt itself to ordinary operating conditions when these extreme demands are met. In addition, the driving members are so arranged that the loads on those components, which are utilized during the greater period of the vehicles operation, are so distributed as to reduce the wear thereof to a minimum. Finally, automatically operable anticreeping means is incorporated to obviate a very dangerous condition met with in the majority of fluid-coupled drives.

With th`ese and other considerations in view, the invention consists of the apparatusV described in this specification, claimed in the claims and illustrated in the accompanying drawings, in which:

Figure 1 is a longitudinal vertical section taken through the transmission oi' this invention.

Figure 2 is a transverse vertical section taken as indicated on the line 2-2 of Figure 1.

Figure 2A is a corresponding view taken as indicated by the line 2A-2A of Figure l.

Figures 3, 6 and 8 are longitudinal views, on a greatly enlarged scale, of a portion of the apparatus shown on Figure l, and more specifically illustrating the operation of the hydraulic clutch operating means, for First and Reverse, Second and Third speeds, respectively. Y

Figures 4, 5, '1, and 9 are schematic drawings of the transmission showing the power transmission through the mechanism for First, Re-

Third speeds, respectively. Figure l0 is a taken as indicated by the line lli-Iii of Figure 1;

Figures l1 to `16 are transverse sections through the clutch operating means at various section lines to show the hydraulic connections transverse section of the view takenv shown as 3 existing at successive stages corresponding to those shown in Figures 3. 6 and 8.

Referring to Figure 1, the reference character indicates generally a transmission having a. housing I2, with a forward flange I3 through which it may be attached to an engine and an universal joint housing I4 at its rear end to accommodate the connection to the rear axle drive means of any of the usual tvpes. At the forward end, the vwheel I5 is bolted and doweled to engine crankshaft I5 and the starter ring gear |1 is mounted in the usual manner. Also, secured to the rear face of the ilywheel I5 adjacent its periphery is the imneller housing I8 of a. Fottinger tvpe fluid coupling I9. Radially spaced vanes 2| are mounted in the housing I8 and cooperating vanes 22 are secured on the rlmner housing 23. Ihis last housing is mounted on a hub 24 which is ,iournaled through an overrunning clutch 25 on the main shaft extension 28. having its forward end piloted in the flywheel at 21 and splined at 28 at its rear end to the main shaft 29. The particular overrunning clutch 25 is more iullv described in a copending application illed herewith, entited Overrunning Clutch. Serial No. 611.974, in the names of Eugene J. Farkas and Joseph W. Rackle, now Patent No. 2,542,914. It suilices here to note that it includes a race 3| having spaced rims 32 joined by separators 33, carrying snrags 34. 'I'hese are urged into driving engagement between the inner surface of the hub 24 and the outer concentric surface of the shaft extension 25 b v a simple single coil spring received in the notches 35.

A sleeve is rotatably mounted on the main shaft 29 and externally journaled by a bearing 31 in the forward ange I3. The central hub 38 of the housing I8 is piloted on the intermediate portion of the sleeve 35, and an oil seal 39 is interposed between the central portion of the ilanle I8 and the external surface of the central hub 38. The imneller housing I8 is drivinglv connected to the forward end of the sleeve 38 through a cushioned clutch plate construction of conventional design oi' which the driven hub 4I is splined at 42 to the sleeve 35, and the driving plates 43 carry a cushion spring 44 and a driving pin 45. The sleeve 35 terminates rearwardly in a splined drum 45 of enlarged diameter, carrying a series of clutch driving discs 41 referred to generally is the second speed clutch 48, as well as that of the third speed clutch 58 later described. are shown in .detail only in the upper half of Figure 1, to avoid unnecessary duplication). A

Continuing rearwardly along the main shaft 29, the principal clutch assembly is shown (the operating portion of this assembly is shown in much enlarged scale in Figures 3, 6, and 8). Essentially, the assembly consists of an inner clutch sleeve 49 rotatably mounted on the main shaft29, an intermediate concentrically arranged longitudinally slidable sleeve valve 5| and the outer concentrically larranged clutch carrier or power transmitting member 52 splined at 53 to the rearward extension 54 of the clutch sleeve 49. The sleeve valve 5| is normally urged rearwardly by two coil springs bearing against the retainer ring 55 cooperating with the longitudinal thrust bearing 55. The primary spring 51 is alone operative on the sleeve valve during the initial stages of its travel, while the secondary spring 58 also comes into operation during the remainder of its travel. It will be noted that there are several co-operating ports in the clutch carrier (this clutch mechanism l will be deferred until later l2, sleeve valve 5I and clutch sleeve 48. The description of their location and function, and of the operation of the springs referred to above in this specification where the operation of the device is considered in detail. It will be suicient to note here that two circumferential chambers separated by the ring 8| are formed between the clutch sleeve 49 and the main shaft 29 and these are designated as the second speed clutch speed clutch supply 58, respectively. A second 82 leads rearwardly through the main shaft 29 to a central cavity 58 in the main driven shaft 54. The cavity 53, in turn. communicates through the lead 55 withthe second speed delivery port 55 of the oil pressure pump 81. On the other hand, the third speed clutch supply 88 communicates through the third speed oil duct 58 and the radial lead 59 with a bore 1| at the rear end of the main shaft 29. The rear end of the duct 58 and the outer end of the lead 59 are closed by plugs 12. The bore 1| is connected by a sleeve 13 extending through the cavity 53 to a similar bore 14 in the main driven shaft 54. A radial lead 15 extends from the bore 14 to a circumferential channel 15 through which communication is eventually established with the third speed delivery port of the pressure pump 51.

The clutch carrier 52 has a hub 11 of considerable length and a disc-like body 18 in which are formed a number (in this case twelve) of opposed clutch operating cylinders designated as 19 for the second speed clutch 48, and 88 for the third speed clutch 58. The carrier proper is completed by a forward shell 8| and a rearward shell 82 mounted on the periphery of the body 18 and all three elements are secured together by the bolts 83. The shells 8| and 82 have inwardly extending flanges 84 and 85. respectively, which serve as abutments for the clutch discs. Clutch operating pistons 85 are mounted in each of the cylinders 19 or 80 on both sides of the body 18 and are responsive to oil pressure supplied through leads extending through the clutch hub 11, the exact location and operation of these being described later. 'I'he clutch operating rings 89 and 98 for second and third speeds, respectively, are mounted forwardly and rearwardly of the body 18. respectively, and have extensions 92 engaging the several pistons 85. A plurality of clutch driven discs 93 having a dished shape are interleaved with the clutch driving discs 41 and are restrained from rotation relative the clutch carrier 52 by the bolts 83. A coil spring 94 normally urges the clutch operating ring 89 toward the carrier body 18 disengaging the discs 93 and 41. A brake drum 95 is formed on the external surface of the rearward shell 82 and co-operates with the reverse brake band 95, received in the recess 91 in the housing I2. These brakes (see Figure 2) are of the form shown generally in Patent 2,020,404, comprising recta around the drum. The adjacent inner ends have eyes |88 and are anchored by longitudinal anchor pins 81 in the anchor housings 88. The outer ends carry the lugs I4I through which the bands are operated.

Continuing rearwardly, the main driven shaft 5I is piloted at its forward end on the bearing 98 on the rear end of the main shaft 29. This carrier 99;

supply 59 and third -tation counterclockwise, to engage (formed integrally with the main shaft 25) and |03 (formed on the forward end of the main driven shaft 64) and three sets of planet pinion clusters each comprising three pinlons 04, |05 and |08, rotatably mounted in the planet carrier 88 and in constant mesh with their respective sun pinions. The carrier 99 has a splined clutch drum |01 extending forwardly therefrom within the clutch carrier 52 and carrying a number of clutch driven discs |08 which co-operate with a number of clutch driving discs |59 secured to the carrier 52. This clutch, designated as the third speed clutch 50, is operated, as was the second speed clutch 40, through the pistons 86 in the cylinders 80, the clutch operating ring 30, and the spring 94.

The planetary clusters referred to above are rotatably mounted on the hollow shafts secured in the carrier 99. The planet pinion |06 runs the entire length of the cluster and the other two planet pinions |04 and |05 are keyed to it and held in position by the retainer ||2, thus giving a substantially integral construction. The carrier 99 is made in two parts, cut transversely of the principal axis and welded together at ||3 on the struts ||4. It extends rearwardly to form the inner race I |5 supporting the forward speeds overrunning clutch ||6, whose outer race is a part of the forward speeds brake drum IIB. The brake band ||9 in the recess |2| and the overrunning clutch ||6 are selectively operable to prevent reverse movement of the carrier 99. A pump housing |22 is secured to the rear end of the housing I2 and supports the main driven shaft 64 in the bearingr |23. The pump housing |22 encloses an impeller having an outer driven member |24 and an inner driving member |25, together with the suction intake |26 and the delivery chamber |21. The pump housing is completed by the cover plate |28, which also supports the universal joint housing I4.

Reference is now made to the lower portion of Figure 1 in which the manually operated control is shown. This comprises a rock shaft |29 journaled on the housing |2 at |3| having an operating arm |32 at its forward end connected through operating linkage |33 (not shown in detail, but including connections leading to an operating lever preferably placed adjacent the steering wheel of the vehicle in which the transmission is installed), two brake operating cams |34 and |35 and a ratchet control |36. Figures 2 and 2A show the precise structural relations of these elements. In Figure 2, the reverse brake operating cam |34 is shown in the position occupied in reverse operation, during which the band 98 engages the drum 95; but adapted, on rothe roller |45 on the pivoted arm |46. This arm also has a cam surface |41 bearing against the lug |48 on the band 36. The arm |46 is urged inwardly by a spring |49 tending to engage the brake; but the spring housing |5| includes an hydraulic chamber |52, which is connected through the duct |53 directly to the delivery chamber |21 of the oil pressure pump 61. A piston |54 is mounted in the cylinder |52 and has a connecting rod |55 to which is attached the spring retainer |56. The rod |55 has a hollow stem |51 and bleeds |58 through which fluid leaking behind the piston |54 may drain to the interior of the housing. The purpose of this construction is to prevent engagement of reverse while the vehicle is moving forwardly. While such movement occurs, the cam |34 is in its rotated position and the arm |48 is the forward speeds brake l l forced to the right against the urging of the spring |49, releasing the brake band 86. This also moves the piston |54 to the right and the chamber |52 illls with oil. Since the oil pump is driven by the final driven shaft 64, so long as that shaft rotates in the forward direction, the chamber |52 is filled with oil and the brake 96 cannot be engaged even if the cam |34 is moved to the position shown in Figure 2. Before the reverse drive can beinstituted, the forward movement of the vehicle must be stopped.

Figure 2A shows the o erating mechanism for H9, which again includes a cam |35 shown in the position occupied in forward operation during which the band I8 engages the drum ||8; but adapted. on clockwise rotation, to engage the roller |31 on the pivoted a-rm |38 to release the brake. The arm is loaded by the spring |39 and has a cam surface |40 at its upper extremity engaging the lugs |4| welded to the outer ends of the band ||9. The ratchet |36 is shown in the same view (of course, in forward speed position) and co-operates with the spring-loaded selector |42 by which the shaft |29 may also be secured in either the reverse or neutral notches |43 and |44. While elements |38 and |39 have been described in the singular, each (as will be apparent from Figure l) comprises two separate arms straddle mounted to engage each end of the respective brake band and to support the respective roller.

Referring to Figure 10, and the extreme righthand portion of Figure 1, the pressure pump and its control mechanism is shown. The pump shown is a well-known type (though any conventional gear pump may be used) and is supplied with oil from the bottom of the housing by the pipe |59 leading to the suction intake |26 and delivers it under pressure to the chamber |21. A pressure relief valve |6| mounted in one side of the housing |22, comprises a plunger |62 normally urged upwardly by the spring |63. When the oil pressure in the delivery chamber |21 reaches a predetermined maximum, the plunger |62 is depressed, permitting flow from the chamber |21 directly to the suction side |26 of the pump. The housing |22 also includes an accelerating valve |64, having a plunger |65 normally urged downwardly by the spring |66. The lower end of the plunger |65 engages an eccentric cam |61 on the control rod |68. Two control arms |69 and |10 are rotatably mounted on the control rod |68 and are connected to the foot accelerator control and a manual accelerator control, respectively. A finger |12 is pinned to the control rod |68 and is so arranged that independent movement of either arm |69 or |10 will be transmitted to the cam |61. The plunger |65 has a section |13 of reduced diameter intermediate its ends and in the plungers lowermost position, the section |13 communicates with a metering bleed |14, whose function will be described later, opening to the transmission housing. The ultimate range of travel of the plunger |65 is regulated by the bolt |15 engaging the upper and lower boundaries of this section |13.

In ordinary operation at third speed, oil under pressure to operate the second speed clutch is delivered from the delivery chamber |21 through the second speed delivery port 66 and the lead 65 (see Figure 1i. Oil for operation of the third speed clutch passes through the lead |18 from chamber |21 to lthe section |13 and thence through the offset lead |11 (indicated in dotted transmission does not revert to iiinorin Figui-o whose longitudinal position corresponds with the circumferential channel on the main driven shaft 54. the radial lead 15 and the sleeve 1l. When an immediate acceleration is desired necessitating the use of the second speed gear ratio, the acceleration valve |55 may be operated automatically through the complete depression of the accelerator pedal; or the transmission may be kept in the second speed ratio through a manual control: in either case, the plunger |65 is raised in response to the resultant rotation of the eccentric cam |51. This will shut o! the communication between the lead |18 to the section |13, thereby reducing the pressure in the third speed clutch supply. I'his action is eiiective only when the control (whether pedal or manual) is substantially completely depressed in response to the demand for increased speed. or other conditions requiring use of the second speed gear ratio. If, on the other hand. a more moderate acceleration is desired, slow but continued depression of the accelerator pedal-ah though the plunger is displaced-does not ailect the operation of the third speed clutch and the the second speed ratio. This is due to the high centrifugal force built up in the clutch carrier, which keeps the fluid in the clutch operating cylinders themselves under sumcient pressure to maintain the clutch engagement despite the fact that the pump may no longer be supplying iluid to them. This will be explained more fully when the operation of the control device is considered in detail.

' Reference is now made to the central portion of Figure l and the lower part of Figure 2. It will be noted that centrifugally operated weights each of the pairs of conduits.

|18 are arranged between each of the pairs of cylinders 19 or 88, and are pivoted at |19 on the carrier 52. Each weight has a crank arm I9| extending through a slot |82 in the carrier hub 11 and operatively engaging a recess |83 in a sleeve valve 5|. It will be apparent that as the carrier 52 rotates at higher speeds, the resultant centrifugal force acting upon the weights 18 will cause the sleeve valve 5| to move to the left against the resistance of the primary and secondary springs 51 and 58. The amplitude oi' this movement is dependent upon the rotational speed of the carrier and the respective resistances of the springs; and it will be observed that as this movement of the sleeve valve takes place, successive ports are brought into alignment with or closed oit from co-operating ports in the hub 11 and the clutch sleeve 49 to establish differing hydraulic circuits.

The exact function and operation of this particular mechanism can best be seen in Figures 3 to 9 and l1 to 16, inclusive. Figures 3, 6, and 8 show the longitudinal arrangement of a representative portion of the control apparatus under various speed and directional conditions, and most of the constituent elements have been iden-` tifled and described in relation to Figure 1. Fig- .ures 1l to 16 show the successive transverse arrangements under similar conditions. Generally, it may be noted that the clutch carrier hub 11, the sleeve valve 5| and the clutch sleeve 48 each have at least two hydraulic leads for each of the cylinders and these leads, due to the relative longitudinal movement oi' these concentric parts. form various channels to and from their respective cylinders. Thus, speed conduit |84 nared lower opening |85. 'I'he hub also has a third speed conduit |86 for each cylinder which the hub 11 has a/secondfor each cylinder. having a terminates in a transversely extending oil groove |81. In addition. it carries a relief conduit |88 for each pair of cylinders midway between the other conduits supplying each of the cylinders in the respective pair and leading from the bore oi' the hub 11 through the ring |89 and permitting oil to waste to the interior oi the housing and thencetothesump |9|.

'I'he sleeve valve 5| also has a second speed conduit |92 and a third speed conduit |85 for each cylinder, arranged in the same axial planes as the conduits |84 and |88 which are, oi' course, the same axial planes as those of each of the individual cylinders 19. In addition. a longitudinally extending oil groove |94 (shown in dotted line in Figure 3) is located on the outer circumference of the sleeve valve 5|, midway between These are thus aligned with the respective relief conduits |88 and intersect the transverse oil grooves |81 referred to above. In addition, the third speed conduit has a small metering oriiice |95, leading to a duct |50 which extends to the rear end of the sleeve valve 5|. This orifice operates in conjunction with the bleed |14 in the accelerating valve |84 previously described. The orifice |95 permits oil to flow behind the sleeve valve as it moves towards the left, and keeps the third speed clutch engaged during merely minor speed variations. However, this must be overruled at the lowest speeds and for idling when the accelerator is released completely and this is accomplished by the bleed |14 which permits a drop in third speed oil pressure at the pump and in the chamber 204 behind the sleeve valve 5 I. so that the sleeve valve 5| is forced to the right by the operation of the springs 51 and 58 and the oil is then forced out of the chamber 204 through the conduit 200 past the bushing 2| which has a slight clearance (see Figure 6). 'I'he sleeve valve 5| has an auxiliary outer sleeve |81 and a somewhat longer auxiliary inner sleeve |98. The latter restricts the travel of the sleeve valve forwardly while the outer sleeve |81, about midway of the travel of the sleeve valve, bears against the retaining ring |99 of the secondary spring 58.

Further movement of the sleeve valve 5| fo wardly is then resisted by both springs 51 and 5I.

The clutch sleeve 48 also has second and third speed conduits 20| and 202 axially aligned with the centers of each of the cylinders and corresponding to the axial planes of the similar conduits in the sleeve valve 5| and hub 11. Again, the second speed conduits 20| are provided with annularly extending grooves 203 corresponding to the similar construction at |85. As pointed out above, the second and third speed clutch supplies 59 and 60 are separated by the ring 5|, thus localizing the supplies of oil for the independent operation of the second speed and third speed clutches.

Reference is now made to Figures 3 through 9 and 11 through 16 as indicating, first, the relative positions of the control apparatus; and, second. in a diagrammatic fashion, the power flow through the transmission from the engine to the driven shaft under each condition of operation.

FIRST SPEED Figures 3, 4, 11, 13 and 15 In Figure 3, the control mechanism is shown at iirst speed operation during which the rotational speed of the clutch carrier is low enough so thatthe centrifugal ceptibly displaced. As a consequence, the sleeve valve 5| remains substantially in its most rearweights |18 are not per-l and |94 to relief conduit |88 (Figure 15).

ward position. Under these conditions, neither the second or .third speed clutches 40 or 50 is operated. as the auxiliary inner sleeve |90. prevents the passage of oil from the supply 59 through the conduits 20| (Figure 1l); and the sleeve valve 5|, proper, blocks the passage of oil frcmirthe supply 60 through the conduits 202 (Figure 13). Moreover, oil in the cylinders 19 is free to drain to the sump through the conduits |04 which are not completely covered by the outer auxiliary sleeve |91 (Figure 11) and from cylinders through conduits |86 and the grooves rI|` 01 he clutches 40 and 50 are then disengaged bythe springs 94.

Under these circumstances. as shown in Figure 4, rotation of the crankshaft I6 is imparted to the impeller housing i8 and thence by hydraulic reaction to the runner 23 and through the overrunnlng clutch 25 to the main shaft 29. The sun pinion |02 drives the planet pinion |05, obtaining the maximum speed reduction and transmitting the torque to the driven shaft 64 through the sun pinion |03 engaging the corresponding planet pinion |06. The forward speed brake ||9 is engaged through the manual control activating the overrunning clutch ||6 to prevent reverse rotation of the planet carrier 99. The clutch carrier 52 sun .pinion |0| constantly meshed with the corresponding planet pinion |04 and is rotated accordingly. However, both clutches 40 and 50 are disengaged and there is no reaction. Under these conditions, the maximum engine torque is transmitted to the driven shaft in the forward direction and at the lowest speed ratio.

REVERSE' Figures 3, 5, l1, 13 and 15 In the reverse operation. the condition of the control mechanism is precisely the same as that for first speed forward. However, whileas described below-first speed operation automatically changes to second speed operation, as the vehicle speed increases through the hydraulic control; increased reverse speeds have no such effect, as the pump which furnishes the oil to operate the hydraulic control is only operated when the Vehicle moves forwardly. It will be recalled that manual operation is necessary to select forward or reverse speeds through the medium of selective brake engagement. Thus, in Figure 5, the drive is again taken from the crankshaft |0 through the impeller I0 and by reaction on the runner 23 and thence through the overrunning clutch 25 to the main shaft 29. As before, the sun pinion |02 drives the planet pinion |05 and, of course, the other planet pinions |04 and |06 are also rotated. However, the forward speed brake ||9 is now released so that the carrier 99 is free of clutch ||6. The reverse brake 96 is engaged and this locks the clutch carrier 52 and its sun pinion |0I. The gearing now functions as a planetary and reverse rotation at the low-speed ratio and maximum torque is imparted to the driven shaft 64 through the planet pinion |06 and the sun pinion |03. SECOND SPEED Figures 6, 7, 12, 13 and 15 It was noted under the description of first speed operation, that the clutch carrier 52 was rotated, but that its rotational speed was not suicient to cause radial displacement of the centhe restraint of the overrunning g mechanical and the fluid trifugal weights |10 and consequent axial displacement of the sleeve valve 5| against the resistance of the primary spring 51. However, as the rotational speed increases, the weights move outwardly and the sleeve valve 5| is projected axially forward until it reaches the position shown in 'Figure 6. The exact speed at which this occurs is, of course, a function of the weight and the spring loading. reached, the second speed clutch 40 is engaged by oil flowing from second clutch supply 59 through the conduits 20|, |92 and |84 to the second speed clutch cylinders 19 (Figure l2) and projecting the pistons 06 forwardly operating the ring 89 to engage the discs 4l and 93. The third speed clutch 50 remains inactive and the control mechanism is functionally unchanged from thatshown in Figures 3, 13 and 15.

In operation, as shown in Figure '1, this locks crankshaft |6, the impeller housing I8' and the associated drum 46 directly to the clutch carrier 52. This, in turn, drives its sun pinion |0| and the triple .planetary pinion through I |04. The drive is again taken off through the planet pinion |06 and its sun pinion |03 on the driven shaft 64. The forward speed brake ||9 is still engaged preventing the reverse rotation of the planet carrier 99, so that forward rotation at an intermediate speed ratio is imparted to the driven shaft. The main driving shaft 29. is, of course, rotated through the pinions |02 and |05, but the overrunning clutch 25 disassociates the runner 23 and permits it free rotation. The drive is entirely coupling is inoperative.

THIRD SPEED Figures 8, 9, 12, 14 and 15 As the rotational speed of the clutch carrier 52 increases, the centrifugal weights |18 will undergo further radial displacement and, in consequence, the sleeve valve 5| will be projected further toward the left against the combined resistance of the primary and secondary springs 51 and 58 until it occupies the .position shown in Figure 8. The use of the separate springs permits a sharper differentiation between the Y two speed ranges and gives a sharper action. As

a matter of illustration, the primary spring 51 is deflected through its initial range by a load of about 10 pounds and the secondary spring 58 through its range by a load of about 25 pounds. Employing these ratios, a proper balance is obtained between the third and second speed ranges and a suiiciently positive action is obtained either with increasing or decreasing speeds with and without sacrifice of smoothness. -While multicoil springs are shown, it is quite .possibleand under some conditions advantageous-to use single coil springs in their' place. These load up much more quickly as they approach ultimate deflection and give an even sharper division between the second and third speed ranges.

Under these conditions, oil under pressure is still supplied to the second speed clutch 40 precisely in the manner described with reference to second speed operation, the flared ends and 203 permitting the continued flow of oil despite' When this position is celerating valve and the speed clutch line norman-a1', both brakes us and ss leased. No specic drawing indicates this con` v braking surface (Figure 18). The longitudinal oil grooves |54 are sumciently displaced from the conduit |08 that oil from the second speed clutch 40 cannot flow out through them nor can oil be admitted from the third speed side. The balance between the discharge rates of the bleed |14 in the acorice .|95 normally keeps the transmission in third speed even when the speed momentarily falls somewhat below the usual operating speed, since the oil passing th h the orifice |95 prevents immediate respo ve movement of the sleeve valve However, this is overruled by the further loss in third pressure by leakage through the bleed |14 when the engine approaches idling conditions. The precise capacities of these orices is a matter of experiment to obtain the requisite balance, but they are important in mainaining the requisite smoothness of operation under all conditions.

Referring now to Figure 9, power is transmitted as shown directly from the crankshaft I5 through the-impeller housing I8 and the drum l46 to the clutch carrier 52. As both clutches l0 and 50 are engaged, this occasions rotation of both the planet carrier 99 and the sun pinion I0| This results in a locking of the triple pinion and the carrier. and the direct drive is taken oil' through the planet pinion |06 and sun pinion |03, and thence to the driven shaft 5I. Again, the main drive shaft 29 is rotated, but this does not drag the hydraulic coupling, as the overrunning clutch permits its free operation. The drive is entirely mechanical and the duid coupling is not utilized. As before, the forward speed brake IIS is energized. but this has no effect since there is no reaction to overcome while the planet carrier is locked with respect to the triple planet gear. The torque is now transmitted at engine speed in the forward sense.

NEUTRAL Figures 1, 2 and 2A are redition, but it will be understood that the neutral notch I of the ratchet |35 is then engaged by the selector |42 and the cams |34 and |35 have displaced the arms IIB and |38 to the right and left, respectively. Under these conditions, theoretically, no torque is applied to the shaft 54. However, as in many transmissions of this type utilizing a fluid coupling, there is actually a tendency to creep which can be very troublesome unless proper provision is made for it. Usually, the emergency brake of the vehicle is relied upon under such circumstances, but this requires specific operation by the driver and. hence, is not entirely safe. 'I'his may be prevented automatically by the anticreep brake shown in Figures 1 and 2 and eifective between the clutch carrier 52 and the planet carrier 99. This includes a brake band 205 having an inner 206 co-operating with a complementary surface 201 on the planet carrier 99. 'Ihe band 205 is cut away at 200 to increase its flexibility, leaving segments 209 which serve as additional masses responsive to centrifugal forces imposed by rotation of the carrier 52 on which the band is mounted in an extension 2I2. The band 205 is split at 2|3 and one end is loosely pinned to the clutch carrier 52 at 2 I 4. The spring 2|5 mounted on the boss 2H on the abutment 2|6 Secured to the carrier 52 normally urges the band 205 into wrapping engagement with the surface 201 on the planet carrier 99. This is effective at the lower rotational speeds of the coupling obtaining during idling to impede relative rotation oi the two carriers and prevent creep. However, at higher speeds, centrifugal force acting on the even at speeds above the normal second speed range, when the third speed'clutch is effective as well. It has been noted above that at higher speeds the centrifugal force, acting upon the oil behind the pistons by reason of the rotation of the Aclutch engaged. Moreover,

carrier, keep both clutches when it is desired to obtain immediate acceleration beyond that afforded by third speed ratio, even though the vehicle is then proceeding in third speed, the fact that the oil pressure is' constantly maintained in the second in engagement at ing for rst.

It will be understood that the term fluid couthe specification and claims is as meaning a fluid power transmay reasonably be included within the scope thereof.

The invention claimed is: l. In a variable speed power transmission, in mbination, a power shaft sasso a planetary gearing system including planet pinion gears mounted on a planet carrier rotatably supported about the axis of said shafts and respectively meshing sun gears, selectively operable torque reaction means associated with said planet carrier for obstructing rotational movement of said planet carrier in one direction, an intermediate rotatable power transmitting member including one of said sun gears. a second sun gear on said main shaft, a third sun gear on said load shaft, manually operable means to secure said power transmitting member against rotation, first clutch means to fix said power transmitting member for rotation with said power shaft, a second clutch, means connecting said second clutch to said power transmitting member, means also connecting said second clutch to said planet carrier, and means for operating said second clutch means only concurrently with said rst clutch means.

2. In a variable speed power transmission, in

combination, a power shaft and a main shaft and a load shaft axially arranged, a [fluid coupling] hydrokinetic unit comprising a power receiving element fixed for rotation with said power shaft and a power delivery element having a one-way driving connection with said main shaft, a planetary gearing system including planet pinion gears mounted on a planet carrier rotatably sup ported about the axis of said shafts and respectively meshing sun gears, selectively operable torque reaction means associated with said planet carrier for obstructing rotational movement of said planet carrier in one direction, an intermediate rotatable power transmitting member including one of said sun gears, a second sun gear on said main shaft, a third sun gear on said load shaft, manually operable means to secure said power transmitting member against rotation, first clutch means to fix said power transmitting member for rotation with said power shaft, a second clutch, means connecting said second clutch to said power transmitting member, means also connecting said second clutch to said planet carrier, and means for operating said second clutch means only concurrently with said first clutch means.

3. In a variable speed power transmission, in combination, a power shaft and a main shaft and a load shaft axially arranged, a [fluid coupling] hydrokinetic unit comprising a power receiving element xed for rotation with said power shaft and a power delivery element having a one-way driving connection with said main shaft, a planetary gearing system including planet pinion gears mounted on a planet carrier rotatably supported about the axis of said shafts and respectively meshing sun gears, selectively operable torque reaction means associated with said planet carrier for obstructing rotation of said planet carrier in one direction only, an intermediate rotatable power transmitting member including one of said sun gears, a second sun gear on said main shaft, a third sun gear on said load shaft, manually vselectively operable manual means to secure said power transmitting member against rotation or to operate said torque reaction means or to hold both said securing means and said reaction means inoperative, first clutch means to ilx said power transmitting member for rotation with saidpower shaft, a second clutch, means connecting said second clutch to said power'transmitting member, means also connecting said second clutch to said planet carrier, and means for operating said 14 second clutch means only concurrently with said first clutch means.

4. In a variable speed power transmissie in combination, a power shaft and a main shaft and a load shaft axially arranged, a [fluid coupling] hydrokinetic unit comprising a power receiving element fixed for rotation with said power shaft and a power delivery element having a one-way driving connection with said main shaft, a planetary gearing system including planet pinion gears fixed for common rotation and mounted on a planet carrier rotatably supported about the axis of said shaft and respectively meshing sun gears, selectively operable torque reaction means associated with said planet carrier for obstructing rotation of said planet carrier in one direction only, an intermediate rotatable power transmitting member including one of said sun gears, a second sun gear on said main shaft, a third sun gear on said load shaft. manually operable selective means effective to secure said power transmitting member against rotation or to operate said torque reaction means or to hold both said securing means and said reaction means inoperative, first clutch means carried on said power transmitting member to fix said power transmitting member for rotation with said power shaft, second clutch means mounted on said power transmitting member, means connecting said second clutch to said planet carrier. means for operating said second clutch means only concurrently with said first clutch means. hydraulic actuating means for said clutches, a valve controlling said hydraulic actuating means, a governor operating said valve to actuate said rst clutch above a predetermined load shaft speed and to actuate both said clutches above a predetermined higher load shaft speed.

5. In a variable speed power transmission, in combination, a housing, a power shaft and a main shaft and a load shaft axially arranged, a [fluid coupling] hydrokinetc unit comprising a power receiving element fixed for rotation with said power shaft and a power delivery element having a one-way driving connection with said main shaft, a planetary gearing system including planet pinion gears fixed for common rotation and mounted on a planet carrier rotatably supported about the axis of said shafts and respective meshing sun gears, selectively operable torque reaction means effective between said housing and said planet carrier for obstructing rotation of said planet carrier in one direction only, an inter mediate rotatable power transmitting member including one of said sun gears, a second sun gear on said main shaft, a third sun gear on said load shaft, selectively operable means on said housing to secure said power transmitting member against rotation, externally operable means effective to actuate said torque reaction means or said power transmitting member securing means or to render both said last-named means inoperative. ilrst clutch means mounted on said power transmitting member and selectively operable to fix said power transmitting member for rotation with said power shaft, second clutch means mounted on said power transmitting means, means connecting said second clutch to said planet carrier, said second clutch means being operable only concurrently with said ilrst clutch means, hydraulic actuating means for said clutches, a valve controllingv said hydraulic actuating means, a governor operating said valve to engage said first clutch above a predetermined load shaft speed and to engage said second clutch above a predetermined higher load shaft speed, and externally operable means to overrule said governor to restrain operation of said clutch above said predetermined higher load shaft speed.

b'. In a variable speed power transmission, in combination, a housing, a. power shaft and a main shaft and a load shaft axially arranged in said housing. a [fluid coupling] hydrokinetic unit comprising a power'receiving element fixed for rotation with said power shaft and a power delivery element having a one-way driving connection with said main shaft, a planetary gearing system including triple planet pinion gears fixed for common rotation and mounted on a planet carrier rotatably supported about the axis of said shaft and respectively meshing sun gears, selectively operable torque reaction means effective between said housing and said planet carrier for obstructing rotation of said planet carrier in one direction only, an intermediate rotatable power transmitting member including one of said sun gears, a second sun gear on said main shaft, a third sun gear on said load shaft, means on said housing in secure said power transmitting member against rotation, externally controllable selectively operable means effective to activate said torque reaction means or said power transmitting member securing means or to render both said last-named means inoperative, rst clutch means mounted on said power transmitting member and selectively operable to fix said power transmitting member for rotation with said power shaft and said power receiving element, a second clutch, means connecting said second clutch to said power transmitting member, means also connecting said second clutch to said planet carrier, said second clutch means being operable only concurrently with said first clutch means. hydraulic actuating means for said clutches, a' valve controlling said hydraulic actuating means. a governor operating said valve to engage said first clutch above a predetermined load shaft speed and to engage both said clutches above a predetermined higher load shaft speed, externally operable means to overrule said governor to restrain the operation ofl said second clutch above said predetermined higher load shaft speed, and manually operable hydraulic means for releasing said second clutch.

7. In a variable speed transmission, in combination, a housing, a power shaft, a load shaft, a [fluid coupling] hydrokinetic unit having one element xed for rotation with said power shaft, a multiple planetary gearing system having one element xed for rotation with said load shaft, a power transmitting member interposed between said [fluid coupling] hydrokinetic unit and said planetary gearing system and arranged for selective operation therewith, means rendering said member inoperative with respect to said [fluid coupling] hi/drokinetic unit and said planetary gearing system and to transmit torque in one direction through said [coupling] hydrokinetic unit and said planetary gearing system at one speed ratio, means locking said member to said housing, means to lock said member to said power shaft and said planetary gearing to eect differential rotation thereof and transmit torque at another speed ratio in said one direction, a clutch, means connecting said clutch to said power transmitting member, means also connecting said clutch to a second element of said planetary gearing system, means applying said clutch to lock said member to said power shaft and said planetary gearing system to effect commo'n rotation 'thereof and transmit torque at a third speed ratio in said one direction, and means rendering said [duid coupling] hydrokinetic unit inoperative while torque is transmitted at said last two speed ratios.

8. In a variable speed transmission, in combination. a housing. a power shaft, a load shaft, a [fluid coupling] hydrokinetic unit having one element ilxed for rotation with s aid power shaft, a multiple planetary gearing system having one element thereof fixed for rotation with said load shaft, a power transmitting member interposed between said [duid coupling] hydrokinetic unit and said planetary gearing system and arranged for selective operation therewith, means rendering said member inoperative with respect to said [fluid coupling] hydrokinetic unit and said planetary gearing system and to transmit torque in one direction through said [coupling] hydrokinetic unit and said' planetary gearing system at one speed ratio, means locki'ng said member to said housing, means to lock said member to said power shaft and said planetary gearing and to eil'ect differential rotation thereof and transmit to lock said member to said torque at another speed ratio in said one direction, a clutch. means connecting said clutch to said power transmitting member, means also connecting said clutch to a second element of said planetary gearing system, means applying said clutch power shaft and said planetary gearing system and to effect common rotation thereof and transmit torque at a third speed ratio in said one direction, means rendering said [fluid coupling] hydrokinetic unit inoperative while torque is transmitted at said last two speed ratios, said member including control means automatically responsive to the rotational speed of said member to operate said last two locking means.

9. In a variable speed transmission, in combination, a housinga power shaft, a load shaft, a [fluid coupling] hydrokinetic unit having one element fixed for rotation with said power shaft, a multiple planetary gearing system having one element thereof fixed for rotation with said load shaft, a power transmitting member interposed between said [fluid coupling] hydrokinetic unit and said planetary gearing system and arranged for selective operation therewith, means rendering said member inoperative with respect to said [uid coupling] hydrokinetc unit and said planetary gearing system and to transmit torque in one direction through said [coupling] hydrokinetic unit and said planetary gearing system at one speed ratio, means locking said member to said housing, means to lock said member to said power shaft and said planetary gearing to effect differential rotation thereof and to transmit torque at another speed ratio in said one direction, means to lock said member to said power shaft and said planetary gearing system to effect common rotation thereof and transmit torque at a third speed ratio in said one direction, means rendering said [flui coupling] hydrokinetic unit inoperative while torque is transmitted at said last two speed ratios, said last two locking means comprising hydraulically activated clutches carried on said member, conduits leading to said clutches, a series of hydraulic valves in said conduits, a device on said member responsive to the rotational speed thereof and effective to operate said valves, a pump driven by said load shaft to deliver fluid under pressure to effect respective operation of said clutches, and means limiting the operation of said valves to permit the application of one said clutch at a predetermined load shaft speed 17 range and of both said clutches at a higher predetermined load shaft speed range.

10. In a variable speed transmission, in combination, a housing, a sump, a power shaft, a load shaft, a [fluid coupling] hydrokinetic unit having one element fixed for rotation with said power shaft, a multiple planetary gearing system comprising a carrier and planet pinions and sun pinions having one element thereof fixed for rotation with said load shaft, a power transmitting member interposed between said [uid coupling] hydrokz'netic unit and said planetary gearing system and arranged for selective operation therewith, means rendering said member inoperative with respect to said [fluid coupling] hydrokinetc unit and said planetary gearing system and to transmit torque in one direction through said [coupling] hydrokinetic unit and said planetary gearing system at one speed ratio, means locking said member to said housing, means to lock said member to said power shaft and said planetary gearing system to effect diiIerential rotation thereof and transmit torque at another speed ratio in said one direction, a clutch, means connecting said clutch to said power transmitting member, means also connecting said clutch to said carrier, means applying said clutch to lock said member to said power shaft and said planetary gearing system to effect common rotation thereof and transmit torque at a third speed ratio in said one direction, and means rendering said [fluid coupling] kydrokinetic unit inoperative while torque is transmitted at said last two speed ratios.

11. The structure of claim which is further characterized in that said last two locking means comprise clutches on said member co-operating with said power shaft and the carrier of said planetary gearing system respectively, hydraulically activated operating cylinders for said clutches, conduits leading to said cylinders, a series of valves in said conduits controlling the flow therethrough, a device on said carrier responsive to the rotational speed thereof controlling said valves, and a pump driven by said load shaft supplying activating fluid under pressure to said conduits.

12. The structure of claim 10 which is further characterized in that said last two locking means comprise clutches co-operating with said power shaft and the carrier of said planetary gearing system respectively, hydraulically activated operating cylinders for each of said clutches, conduits leading to said cylinders a series of valves in said conduits controlling the hydraulic ow therethrough, a device on said carrier responsive to the rotational speed thereof controlling said valves, a pump driven by said load shaft supplying activating fluid under pressure independently to said conduits, and an accelerator controlled valve selectively operable to interrupt the iiow of such fluid to one of said conduits.

13. The structure of claim 10 which is further characterized in that said last two locking means comprise clutches on said member co-operating with said power shaft and the carrier of said planetary gearing system respectively, hydraulically activated operating cylinders for said clutches, conduits leading to said cylinders, a slidable sleeve valve interposed in said conduits controlling the flow therethrough, a device on said carrier responsive to the rotational speed thereof and eective to move said sleeve valve axially, a pump driven by said load shaft supplying activating iluid under pressure independwhich 18 ently to said conduits, a first spring means resiliently resisting the movement of said sleeve valve in response to said device through an initial predetermined range, a second spring means resiliently resisting the further movement of said sleeve valve in response to said device through a second predetermined range, said sleeve valve being so arranged that said conduits to one said clutch are opened at the end of said iirst range and that said conduits to the other said clutch are also opened at the end of said second range.

14. 'Ihe structure of claim 10 which is further characterized in that said last two locking means comprise clutches on said member co-operating with saidA power shaft and the carrier of said planetary gearing system respectively, hydraulically activated operating cylinders for said clutches, conduits leading to said cylinders, a slidable sleeve valve interposed in said conduits controlling the dow therethrough, a device on said carrier responsive to the rotational speed thereoi effective to move said sleeve valve axially. a pump driven by said load shaft supplying activating uid under pressure independently to said conduits, a iirst spring means resiliently resisting the axial movement of said sleeve valve in response to said de ce from an initial position in which said conduits are closed to an intermediate position in which fluid is admitted to one said cylinder, a second spring means resiliently resisting further axial movement of said sleeve valve from said intermediate position to a nal position in which fluid is admitted to the other said cylinder, said one cylinder being continuously activated after said sleeve valve passes said intermediate position.

15. The structure of claim 10 which is further characterized in that said last two locking means comprise clutches on said member co-operating with said power shaft and the carrier of said planetary gearing system respectively, hydraulically activated operating cylinders for each of said clutches, conduits leading to said cylinders. a sleeve valve effective on axial movement to control the flow through said conduits, a device on said carrier responsive to the rotational speed thereof enective to move said sleeve valve axially, a pump driven by said load shaft supplying activating iluid under pressure independently to said conduits, a rst spring means resiliently resisting the axial movement of said sleeve valve in response to said device from an initial position in said conduits are closed to an intermediate position in which fluid is admitted to one said cylinder. a second spring means resilientLv resisting further axial movement of said sleeve valve from. said intermediate position to a final position in which fluid is admitted to the other said cylinder, said valve having passageways communicating with said conduits as the rotational speed of said carrier decreases and said sleeve valve is returned to its initial 'position under the urging of said spring means and simultaneously communicating with the sump to drain oil from said cylinders.

16. The structure of claim 10 which is further characterized in that said last two locking means comprise clutches on said member co-operating with said power shaft and the carrier of said planetary gearing system respectively, hydraulically activated operating cylinders for each of said clutches, conduits leading to said cylinders, a sleeve valve effective on axial movement to control the flow through said conduits, a device on said carrier responsive to the rotational speed which uid is admitted to one said cylinder, a

second spring' means increasingly resisting further axial movement of said sleeve valve from said intermediate position to a nal position in which fluid is admitted to the other said cylinder, said valve having passaizeways communicating inversely'successively with said conduits, as the rrotational speed of said carrier decreases and said sleeve valve is returned in its initial position under the urging of said spring means and simultaneously communicating with the sump to drain oil from said cylinder.

17. The structure of claim which is further characterized in that said last two locking means comprise clutches on said member co-operating with said power shaft and the carrier of said planetary gearing system respectively, hydraulically activated -operating cylinders for said clutches, conduits leading to said cylinders, a sleeve valve interposed in said conduits controlling the flow therethrough, a device on said carrier responsive lto the rotational speed thereof adapted to move said sleeve valve axially as the speed increases. a pump driven by said load shaft supplying fluid under pressure independently to' said conduits, a first spring means resiliently resisting the axial movement of said sleeve valve in response to said device from an initial position in which said conduits are closed to an intermediate position in which uid is admitted to one said cylinder, a second spring means resiliently resisting further axial movement of said sleeve valve from said intermediate position to a iinal position in which fluid is admitted to the other said cylinder, and hydraulic means initially resisting the return of said sleeve valve from said final position when rotational speed of said carrier decreases.

18. A structure of claim 10 which is'further characterised in that said last two locking means comprise clutches co-operating with said power shaft and the carrier of said planetary gearing system respectively, hydraulically activated operating cylinders for said clutches, conduits leading to said cylinders, a sleeve valve interposed in said conduits and eiective to control the flow therethrough, a device on said carrier responsive to the rotational speed thereof land adapted to move said sleeve valve into successive positions of co-operation with said conduits, a pump driven' by said load shaft supplying activating fluid 'under pressure independently to said conduits, a

first spring means ment of said sleeve valve in response to increased /20 resilientlyresistingthemovespeed of the carrier from an initial position in which said conduits-are closed to an intermediate position in which fluid is admitted to onev said cylinder, a second spring means resiliently resisting further movement o! said sleeve valve i'rom said intermediate position to a nal position in which iiuid is admitted to other said cylinder, and ex operated overriding means effective at saidpump to interrupt the ow of uid to the other said cylinder.-

19. In the structure of claim 10 which is further characterized in that said control means comprise a pump driven by said load shaft and supplying activating iiuid under pressure to operate certain of said locking means, and said locking means effective between said member and said housing includes a cylinder supplied with fluid from said pump and effective to restrain the engagement of said locking means so long as said load shaft is operating in said one direction.

20. 'I'he structure or claim 10 which is further characterized in that said planetary gearing system includes a planet carrier, a centrifugally operated brake carried by said member and adapted to co-operate with said carrier to restrain relative rotation therebetween at idling speeds and to be disengaged therefrom as the rotational speed of said carrier increases.

EUGENE J. Fannie.

REFERENCES CITED UNITED vS'IM'ris PATENTS Number Name Date 1.199.359 Eottinger Sept. 26, 1916 2,103,540 Livermore Dec. 28, 1937 2,147,528 Fottinger Feb. 14, 1939 2,303,975 Banker Dec. 1, 1942 2,329,724 Maurer Sept. 2l, 1943 2,332,593 Nutt Oct. 26, 1943 2,339,628 Dumeld Jan. 18, 1944 2,343,955 Cotterman Mar. 14, 1944 2,371,574 Swennes- Mar. 13, 1945 2,377,696 Kelley June 5, 1945 OTHER REFERENCES Publication, Hydraulic Drive-Twin Disc Clutch Co., Bulletin #132, pages 4 to l0 inclusive, Racine, Wisconsin, Dec. 18, 1941.

Publication, S. A. E. Journal, vol. 15. #4, pages 433 to'v443 incl., October 1939.

Publication, Torque Converters, P. M. Heldt Co., Nyack, New York, 3rd edition. Pases 78 to 79 inclusive. 

